About Idarucizumab (Praxbind)

This page provides supplementary information for the Idarucizumab (Praxbind) Dose Calculator. Idarucizumab is a specific reversal agent for the direct thrombin inhibitor dabigatran (Pradaxa®). It is a humanized monoclonal antibody fragment (Fab) that binds to dabigatran and its metabolites with high affinity, neutralizing their anticoagulant effect.

The use of this reversal agent is indicated in adult patients treated with dabigatran when rapid reversal of its anticoagulant effects is required for emergency surgery/urgent procedures or in life-threatening or uncontrolled bleeding.

Outputs Explained

The calculator provides the standard, evidence-based dosing recommendation for idarucizumab.

• Recommended Dose: The standard total dose is always 5 grams.
• Vials Required: The medication is supplied as two 2.5 g / 50 mL vials, so two vials are required to make up the total 5 g dose.
• Administration Instructions: Provides a summary of how to administer the dose, either as two consecutive IV infusions or as a direct IV push (bolus).
• Second Dose Considerations: A conditional note appears if you indicate a previous dose was given. This outlines the specific, rare circumstances where a second 5 g dose may be considered, such as re-bleeding with evidence of dabigatran re-exposure.

How to Use the Calculator

This tool is designed for rapid dose confirmation in a clinical setting. Follow these two simple steps:

1. Select the Indication: Choose whether the reversal is for an emergency surgery/urgent procedure or for life-threatening/uncontrolled bleeding. This does not change the dose but is included for context.
2. Indicate Previous Dose: Check the box if a 5 g dose has already been administered for the current event. This will trigger a note regarding considerations for a second dose.

The output updates automatically based on your selections.

Dosing Overview

The recommended dose of idarucizumab is a single 5 g administration. The dose is not adjusted for patient weight, age, or renal function.

Administration

• The 5 g dose is provided as two separate vials, each containing 2.5 g of idarucizumab in 50 mL of solution.
• Both vials should be administered to the patient.
• Administration Options:
  • As two consecutive intravenous infusions, each over 5-10 minutes.
  • As a single intravenous bolus injection (pushing the contents of both vials consecutively).
• A pre-existing IV line should be flushed with sterile 0.9% sodium chloride solution before and after administration.

Switching and Re-initiation

After dabigatran’s anticoagulant effect has been reversed, patients remain at risk of thrombosis due to their underlying medical condition. It is important to re-initiate antithrombotic therapy as soon as medically appropriate.

• Dabigatran (Pradaxa®): Treatment can be re-initiated 24 hours after administering idarucizumab, assuming the patient is clinically stable.
• Other Antithrombotics: Other agents, such as parenteral anticoagulants (e.g., low-molecular-weight heparin), may be started at any time if the patient is clinically stable and hemostasis has been achieved.

Missed Dose

Idarucizumab is administered as a single 5 g dose in an emergency setting, so the concept of a “missed dose” does not apply. The primary concern is whether the initial dose was sufficient. If bleeding recurs or laboratory parameters indicate a rebound of dabigatran activity, a second 5 g dose may be considered. This decision should be based on clinical judgment and consultation with a specialist.

Safety Alerts

Key safety information includes:

• Thromboembolic Risk: Reversing dabigatran therapy exposes patients to the thrombotic risk of their underlying disease. The risk of thromboembolic events was observed in the RE-VERSE AD trial. Antithrombotic therapy should be resumed as soon as it is medically appropriate.
• Hypersensitivity Reactions: There is a potential for hypersensitivity reactions. The risk is low, but clinicians should be prepared to manage any allergic-type reactions.
• Hereditary Fructose Intolerance: Each 5 g dose contains 4 g of sorbitol. In patients with hereditary fructose intolerance, this can lead to serious adverse reactions. This condition should be considered before administration.

Frequently Asked Questions

References

1. PRAXBIND® (idarucizumab) Prescribing Information. Boehringer Ingelheim Pharmaceuticals, Inc. Ridgefield, CT. View FDA Label
2. Pollack, C. V., Reilly, P. A., Eikelboom, J., et al. (2015). Idarucizumab for Dabigatran Reversal. New England Journal of Medicine, 373(6), 511–520. DOI: 10.1056/NEJMoa1502000
3. PRAXBIND® Official HCP Website. Boehringer Ingelheim. Visit Website
4. Glund, S., Stangier, J., Schmohl, M., et al. (2015). Safety, tolerability, and efficacy of idarucizumab for the reversal of the anticoagulant effect of dabigatran in healthy male volunteers: a randomised, placebo-controlled, double-blind phase 1 trial. The Lancet, 386(9994), 680-690. DOI: 10.1016/S0140-6736(15)60732-2